sumo diaper offers a sustainable seaweed-fibre solution to disposables

product designer luisa kahlfeldt has designed a sustainable baby diaper that uses a textile made from eucalyptus and algae extracts. named after the japanese style of wrestling, the ‘sumo diaper’ project brings the first mono-material diaper to market.

images courtesy of luisa kahlfeldt

the sumo diaper is made entirely of a fabric called seacell, which is antibacterial, antioxidant-rich, and soft, making it the perfect combination for baby’s skin. mono-materiality is considered the ideal product concept for recyclability as once it enters the recycling stream it can be mechanically recycled without waste, extra handling, time or cost.

‘every diaper is constructed of three distinct layers, each performing a separate task,’ explains kahlfeldt. ‘the inner layer sits directly next to the babies skin and has to be very soft and absorbent. the next layer is the absorbing core of the diaper, where the moisture is soaked up.’

‘the last layer of the diaper has to be waterproof and prevent any liquids from leaking out. in order to achieve this, I collaborated with swiss brand schoeller, who developed a material innovation called ecorepel, which is a waterproofing technology that is environmentally friendly and biodegradable.’

‘by impregnating seacell with ecorepel, it withstands abrasion and repeated machine washings, making it a durable and sustainable alternative to the laminated polyester fabrics that are conventionally used.’

according to kahlfeldt, 17 million diapers are disposed of each day in the EU alone making them the third largest single item contributor to landfills. composed of a mix of cellulose fibres, super-absorbing polymers, and synthetic fabrics, a diaper takes up to 500 years to decompose. they also contain potentially harmful chemicals and toxins.

most cloth diapers feature absorbing fabrics that are laminated polyester and polyurethane. additionally, nearly all cloth diapers use nylon hook and loop tape or plastic snap buttons that are impossible to remove later on.

‘my first prototypes explored ways to create a diaper that was fit for deconstruction, and thus improve recyclability,’ she says. ‘I explored a modular construction where the velcro tape or buttons sit on a separate belt. another challenge was to find a replacement for the stretchy parts of the diaper which until now could only be achieved by using a synthetic elastic band.’

‘I prototyped several ways the textile could be more flexible and grow with the child, such as the idea of using a drawstring in the leg area of the diaper that can be pulled tight and loosened depending on need. in the end, I utilised a material innovation called natural stretch, which is an innovative method of knitting natural yarns in order to give them up to 20% natural elasticity, without the use of synthetic yarns.’

kahlfeldt won the BG sustainable development award, by the swiss-based engineering consultancy, which honoured the sumo diaper project for its expertise in the entire marketing chain: materials, production, design, communication. it also won a vitra special award for this project, and the 2019 swiss james dyson awards.

project info

company: luisa kahlfeldt
name: sumo diaper